1. Field of the Invention
This invention relates generally to internal combustion engines, and more particularly to an engine with an offset crankshaft.
2. Brief Description of the Prior Art
The internal combustion engine is well known in the prior art. Examples of prior art references are Campbell U.S. Pat. No. 1,091,629; Pulman U.S. Pat. No. 1,201,098; Penning U.S. Pat. No. 1,317,939; Swensen U.S. Pat. No. 2,236,738; and Sanchez Great Britain Pat. No. 24,568.
Campbell U.S. Pat. No. 1,091,629 discloses a four cycle engine using two pistons in the same cylinder, connected with the crank shaft by an improved system of rods and rockarms or cranks having a small number of parts adapted to efficiently transmit the forces to which they are subjected, whereby one piston effects the suction of the charge at a relatively slow rate, and the scavenging of the cylinder, the other piston serving to compress the charge at a relatively rapid rate and execute the power stroke. The objective of this arrangement of crankshafts is to allow for driving the two pistons in opposition and provide a stroke of the pistons for every 360.degree. revolution of the crankshaft. The power stroke is no more than 90 of rotation of the crankshaft.
Pulman U.S. Pat. No. 1,201,098 discloses an engine of the kind or class in which the working pressure is exerted between two pistons moving in opposite directions in the working cylinder, and operating a single crank. This Patent claimed the combination of two oppositely-moving pistons, a single cross-head operated by the joint action of said two pistons, and moving in the same direction as one of the pistons, and a crank driven from such cross-head and common to the two pistons, in an internal-combustion engine.
Penning U.S. Pat. No. 1,317,939 discloses a combustion engine wherein the cylinders are arranged in pairs, each cylinder having two pistons, between which the explosion occurs, the movement of the pistons being transmitted to a single crank shaft by means of rockers and connecting rods. The power stroke is no more than 180.degree. in this engine. The object of this invention was to provide improvements more especially applicable to two cycle engines, and also various improvements in details of construction and oiling, whether of the type employing carburetors for forming the explosive charge, or of the Diesel or semi-Diesel types.
Swensen U.S. Pat. No. 2,236,738 discloses a novel power transmission mechanism whereby the reciprocating movement of the cylinder-and-piston engine will be converted into rotary motion, or conversely, rotary motion of the power-driven shaft may be converted into reciprocating movement in a cylinder-and-piston machine, such as a pump or air compressor. The power stroke is no more than 180.degree. in this engine. That invention may be employed in connection with a single cylinder-and-piston engine or in connection with a multi-cylinder-and-piston engine. However, the preferred embodiment employed a plurality of such engines in connection with a rotary shaft having a plurality of oblique cranks set in such a way that the endwise thrust on the rotary shaft will be neutralized.
Sanchez Great Britain Pat. No. 24,568 discloses an engine of the rotary type in which the cylinders are arranged in the form of a star, such as were intended for aviation in 1914. The invention is a sleeve-valve engine. The power stroke is no more than 180.degree. in this engine.
The present invention is distinguished over the prior art in general, and these patents in particular, by a new and useful improvement to internal combustion engines which is an engine with an offset crankshaft. When the crankshaft is rotated in a clockwise direction, the distance the piston travels from the top of the stroke (piston at maximum travel) to the bottom of the stroke (piston at the bottom of its travel) is greater than the diameter of the crankshaft rotation. The angle through which the crankshaft moves during the downstroke is greater than 180.degree.. The engine therefore has a longer time power stroke than exhaust stroke. The intake cycle is longer in time than the exhaust cycle which improves aspiration of the engine. This concept can be applied to Otto cycle engines, Diesel engines, two stroke engines, and may be applied to compressors. When used in compressors, the intake stroke is extended which improves aspiration.